The Derp File
by Killerbluetack
Summary: Derpy Hooves is, like most pleasant ponies, hiding a secret. The truth is she's an Agent, dedicated to eradicating the Effects, monsters from Celestia-knows-where.


Derpy casually munched on the muffin, laid out on the table before her. If you asked her if she thought monsters were real five years ago she would have said 'no', if you asked her now she would also say 'no', but she would be lying. A small glass container rested on the table next to her. A worn cork prevented the contents from escaping, which was certainly a good thing. The silvery-grey contents seemed to seethe and flow without deference to gravity or motion, as if the container was it's own miniature universe, where physics textbooks were scrap paper.

Derpy was an agent. She had been for the last few years. Assigned to deal with the supernatural Effects in Ponyville. 'Effects' was just an umbrella term used to describe the supernatural beings that can't be seen or detected by pony-folk. Derpy was one of these happy ponies, until her accident five years ago. The same accident that had damaged the muscles in her eyes had given her an awareness of the Effects. After that it was only a matter of time until the Agency found out. They were an organisation, founded by Princess Luna before her Nightmare Moon phase consisting of ponies like herself. Ponies that could see the Effects.

The Agency was founded in order to keep ponies in the dark regarding the Effects. Nopony really knew what caused them, but directly blasting them with magic made them grow, so pegasi and earth ponies may revolt against the unicorns, thinking they cause the Effects. Of course, they may not, but the risk was too great. And most ponies couldn't see the Effects, so they could just lock agents up in a mental institution, letting the Effects run rampant. But Effects weren't ultimately evil, if anything, they appeared animal. They just wanted to grow as large as they could and reacted badly to being killed.

The problem came when Effects came into conflict with ponies. Effects rapidly grew when they devoured magic, and even the most mundane earth pony had a large amount of magic in their bodies. When ponies started going missing, multiple agents were called to help deal with the rampant Effect. That didn't happen often, but not all Effects are noticeable, and not all grow slowly, but for the most part they were able to deal with the Effects before they became a real danger.

Derpy unfurled the letter, delivered to her door this morning. Celestia herself asked if she could check up on her student Twilight and poke around for anything out of the ordinary. Celestia always signed as the 'Matron', she couldn't be seen going around writing letters to random ponies across Equestria, it would arouse suspicion. Derpy understood her concern, if she had a favourite student, she would probably want to make sure they were safe, she didn't have a favourite student, or a student of any kind though. Her employer had left a note to be delivered to Twilight, an excuse to look around the library a bit. The character that was Derpy's everyday life wasn't really the reading type.

It wasn't that she chose to play somepony mentally-handicapped. It just sort of fell into her lap. Her crossed eyes helped greatly in maintaining the disguise. It had started when she had been caught breaking into Berry Punch's house a few years ago, back when she first arrived in Ponyville. It was definitely easier to avoid the police if ponies thought you just got lost and were a little 'special', in quotations.

She picked up the envelope. Her mouth naturally formed the most dangerous kind of smile, crooked and inherently good-natured. She left the half-eaten muffin on the table. Grasping the letter gently in her mouth she made her way to the library at a brisk trot. The energetic Pinkie Pie was making her daily rounds, randomly stopping ponies in the street and forcing them to socialize with her.

Derpy didn't want any delays, her smile unchanged, she picked up the pace a little bit. Pinkie Pie's sight must be based on movement, Derpy thought to herself, as soon as she began to get a decent speed going, the pony noticed her. Derpy tried to ignore her, but she was getting closer, her bouncing a surprisingly fast method of travel.

'Hey Derpy!' She grinned. Derpy didn't say anything, hoping Pinkie Pie would notice she had a letter in her mouth. 'Can't talk huh?' She craned her head to the side. 'Oh Rarity! Rarity!' Rarity didn't seem to be in the talking mood. Hopefully it would occupy Pinkie long enough; Derpy took the opportunity to slip away.

The envelope grew damp with saliva. She had learned how to minimize drool-damage, as somepony so eloquently put it, but it was ultimately unavoidable. She rapped her hoof against the door, nothing. She tapped again, louder this time.

'Hello Derpy.' Twilight instantly recognised the crossed eyes and blonde mane. Derpy held the mail forth. Twilight's horn glowed and Derpy released the letter. Twilight thanked Derpy as she set the mail down on the table. Derpy looked expectant. 'Come in.' Twilight conceded.

'Thanks.' Derpy feigned happiness. She was good at that. She felt it, the throb of the Effect, pounding in her skull. Her face twitched unnoticeably, she wobbled on her feet slightly. The purple dragon put his claw against her shoulder, steadying her.

'Are you ok?' he inquired, genuinely concerned.

'I'm fine Spike.' She lied. He seemed to believe it. Derpy saw the outline of the basement door in hard darkness. The kind of dark that doesn't come from the absence of light, but the overpowering of it. She would break in later with her basic kit and investigate further while Twilight was asleep.

'Thanks Derpy. I'm not sure why Celestia would send me a note through a mailpony when Spike's right here.' Celestia was obviously very worried about her student, Celestia, with all the trappings of godhood, just couldn't think some things through.

Derpy slipped the torsion wrench and pick into the lock. She felt the tumblers click into place, one by one. The thought of her payment filled her mind, she needed a few things. It was the special kind of need that only came about when she had enough money, she quenched the thought. This was simply observation, if she could find something that hurt the Effect this time she could come back with more of it. This was the most critical phase, and one of the most dangerous, if she was caught it would be difficult to explain why she had a full kit of lockpicks and Everburn oil. She grimaced at the last time she had to use Everburn. While it was possibly the most reliable way to kill an Effect she didn't use it all the time, not everypony had house insurance.

The lock now cooperative, she turned the torsion wrench. The faint clicking of the lock and creak of the door were swift, blending into the background noise of Ponyville's nocturnal residents. Derpy quickly checked the beds, the bumps beneath the blankets were steadily rising and falling. Phew, Derpy thought, still asleep.

The door to the basement stuck. Intelligent Effects were always the worst kind. It was easy to deal with an Effect who turned the doorknob into a mass of tentacles or a tongue to try and dissuade you, but a stuck door couldn't be conquered by latex hoof-covers.

It eventually gave, the Effect wasn't particularly strong yet, a bit of force was all she needed. The loud thunk as the door swung open made her wince. She rechecked the beds, Twilight rolled over, the dragon didn't even stir.

The stairs to the basement were unnaturally slick. Another smart move, slips, especially on stairs, could be serious. Patisserie, one of the best agents she had ever met had been forced into an admin job by a bad fall. Derpy crinkled her nose, that was possibly the worst way to put out of commission. No battle, no great last stand, just an accident and an apology, followed by a swift transfer.

She carefully made her way down the stairs, her saddlebags carefully packed to avoid any sound or breakages. Derpy didn't want to think about the last breakage, even now Lyra sat on benches strangely. Her hooves touched the dry floor, unable to cause her to fall to her death, the Effect had retreated. Derpy felt more than saw the darkness that crept from the edges of the cupboard, spilling out into the room.

As she approached the cupboard it's hinges and knobs melted into the wood, the lines that divided the doors fused together. The Effect didn't want her to open it, which meant that was probably what she should do. She searched for anything on the cupboard that could be opened. Well, there was nothing for it. If she had some special equipment it might have been a different story, but tonight was for observation, and she didn't want to risk leaving it until tomorrow.

A loud crack left the tattered the unnerving silence. The splintered remains of the cupboard door fell away, the hoof-hole disguised in the general obliteration. General rustling emanated from upstairs. She would have to work quickly, before one of them worked up the courage to peek into the basement. The hard black of the Effect tried to retreat even further into the cupboard, wanting to restore the strength it had used slicking the stairs and altering the doors. It's mass spilled out, water too large for it's cup.

She rummaged in her pack. It was, at it's essence, a shadow, so a torch could prove a valuable tool. She slipped her hoof into the harness, casually flicking the torch on, she shone it near the centre of the cupboard. The Effect parted, flowing like water around an island. Maybe something with stronger, more concentrated light would hurt it. She would have to stock up on things that generate a lot of light before dealing with it.

Some more rustling upstairs, some raised voices about who would go down and check first. Derpy tucked the torch back into her saddlebags.

A strange numbness spread throughout her body, followed by a feeling as disquieting as it was alien. She looked back at the cupboard. A long, black feeler had wrapped itself around her shadow and was dragging it towards an unseen mouth that lurked somewhere in the darkness. She wasn't sure what would happen if it got a hold of her shadow, but it probably wouldn't be good.

She slammed her hoof where her shadow was dragged across the ground. It clung to it's owner, the laws of normality forcing it to attempt to return to her. Derpy plunged her head into her saddlebags, the torch would do no good, the Effect would just flow around it. Derpy gripped the laser pointer in her mouth, biting down unnecessarily hard on the switch, a small red dot appeared on the wall.

She brought her weapon to bear on the Effect. Flicking her head from side to side, the red light skittered along the floor. When it touched the Effect's feeler she heard a tiny sizzle and smelled burnt nothingness. She swept the red dot along the full length of the tentacle, the Effect withdrew into the cupboard, leaving some of itself behind to sizzle into the floor. She didn't relish explaining the stain to Twilight.

Her shadow melded silently back into her, she was grateful that the foreign feeling was pushed out of the areas her shadow now filled. The door to the basement exploded. A small dragon, wielding a broom like a battleaxe charged into the room. A wall put an abrupt end to his glorious crusade. Derpy slipped back into her 'character'.

'Hey Twilight!' She greeted. 'What are you doing in my house?'

'Derpy. This is **my** house.' Twilight looked at Derpy with motherly concern. Spike was sceptical. She avoided the small dragon's eyes, the silent fear that somepony would pierce her disguise welled up in her, knotting her stomach. Her face didn't show her turmoil. Twilight gaped at the smashed cupboard, the Effect had retreated back into dark corners, Derpy could barely see it out of the corner of her eye.

'It is?' Derpy's voice held child-like confusion.

'Yes.'

'Sorry Twilight.' Her smile was disarming, she should know, that was how it was designed. Her veneer of innocent stupidity prevented Twilight from becoming anything more than vaguely annoyed. Even as the splinters of her research cupboard rested on the floor, painfully in view, she couldn't bring herself to be mad at the pegasus. She received no opposition as she trotted out of the house. She knew what hurt it, she would stock up at home.

The owner of the hardware store had given her odd looks as she bought a dozen of the strongest LED lanterns available. But it had been a long time since he had stopped questioning Derpy's purchases, why waste energy? Her new purchases gripped in her teeth, she made her way to her house. A large, ornate chariot blocked her path. A purple unicorn was shuffling into the carriage part, what Twilight considered some light reading accompanied her. Derpy felt sorry for the pegasus guards. Derpy grinned, not with her face, but with her whole body, and if anypony had bothered to notice her they would have suddenly felt an urge to run home, climb into bed, and pull the covers all the way over their head.

Her bags full of the powerful electric lanterns, she made her way to Twilight's house. Whatever business Twilight was going away on didn't matter, she had to capitalize on whatever time the house was empty. Skulking and sneaking was fun, but tiring, and she just wanted to deal with this one before it got really big.

The lock wasn't as difficult, nopony really had complex locks in Ponyville, and a few didn't lock their doors altogether, it made her job much easier. The door swung ajar easily, she didn't have to worry about being heard, but it was still a good idea to avoid being spotted, especially in the middle of the day.

She stared at the small dragon clutching the feather duster. She cursed herself for her stupidity, she hadn't seen Spike leaving with Twilight. She had broken into their house, had the lockpicks still in her mouth, a bag full of electric lanterns along with her general supplies saddlebags and the pocket that contained the interesting liquid in the little glass container. This would be difficult to explain.

'You're the one that Celestia sent?'

This wasn't a common question. Derpy could deal with 'What are you doing in my house?' or even 'Who are you?', those she heard more often than Spike's approximate of 'I've been expecting you.'. She wasn't used to being expected, it was something that happened to other ponies.

'I don't know what you're talking about.' It was a worn-out lie, but it conveyed everything she wanted, so it was appropriate. Spike's expression lost it's flavour.

'You're here about the thing in the basement. The shadow-thing.' His voice cracked under his fear.

Derpy took a step back. 'You can see them?'

'Of course, you ponies are practically blind, you can't even see infrared or ultraviolet.' His tone indicated that the biology of a dragon eye was common knowledge and how could she not know something so basic as the spectrums of light that dragons could see. The little dragon was beginning to rankle her.

'Yes. I am here to get rid of the thing in the basement.' She suppressed her annoyance marginally successfully.

'Okay. Ummm...Good luck.' Spike was obviously afraid of the shadow-thing, smart boy. Derpy brought herself to the basement door, there was no need to be silent, although she naturally crept with somepony else in the room.

'Wait!' Spike called to her. The fear still bubbled in his eyes. 'I wan't to help.' Derpy didn't say anything, but her look told him all he needed to know. 'I won't stand by.' He persisted, 'I won't stand by while something eats our home! Not while I can do something, anything, to help.' The fear had melted away, his manner held steel. Derpy smirked a little, she had seen him breath fire, it wasn't powerful heat-wise, but it generated a lot of light, so he wouldn't be totally useless.

'All right.' Derpy was unsure, but that wasn't unusual. Spike hurried behind her, his bravery allowing him to enter the basement, but not to prise himself from behind her back. They descended the stairs. Derpy hoped the Effect hadn't grown much bigger since their last meeting. Spike flicked on the light. Derpy snapped around in surprise, turning on the lights in houses she was breaking into wasn't exactly a high priority. She didn't begrudge the illumination, but it put her out of her element. She didn't like working where she didn't have to worry about being caught.

She set out the LED lanterns on the stairs as she came down. Their harsh light forced her to squint. Spike didn't seem bothered, but why would he, he was a dragon, he had super eyes, she was just a pony. What would she know? She caught herself pulling the faces that accompanied these statements. She was glad Spike was behind her.

The cupboard clearly indicated that Spike believed duct-tape had made all other carpentry tools obsolete. The handle didn't change as she approached, at least she would be spared that trial. The doors rattled open. There was nothing. Nothing! Derpy searched frantically inside the cupboard, only a small corner held any shadows. A small twinge in the back of Derpy's mind, in the part of everypony's brains that recognise when things are about to go bad before the brain actually starts working, saved her life.

She dove backwards as the cupboard exploded. The shadow-thing was no longer just a shadow, but solid. It reared it's great, dark mass, then settled, spreading like treacle over the floor. It raised large tentacles into the air. Derpy jumped out of one of the tentacle's way as it smashed down into the ground. The lantern crushed beneath it. Another crash, the area dimmed slightly as another lantern met it's end.

Derpy had to get out, fast. She shouted at Spike to move. The only thing that held it back was the lanterns, once it was done with those, she pushed the thought to the back of her mind. Once she was out she would have to stock up on Everburn and Ponyville's library would be a thing of the past, if she didn't, Ponyville could be a thing of the past.

A small whippet lashed around her saddlebags, she kicked them loose as they tumbled down the stairs to rest at the bottom. Spike was just behind her, too far behind her. The shadow grabbed his ankle, dragging him toward the seething mass that worked it's way slowly up the stairs. Spike desperately searched in her saddlebags, now right beside him, for something that would help him. Derpy knew there was nothing in there that could save them. Derpy pushed herself onwards, she comforted herself that he knew the risks, but he didn't, not entirely. It hollowed her, but she didn't have the time to feel guilty.

The door seemed so close when her jaw nearly broke. She could barely think for the pain. The Effect used her slip to wrap one of it's appendages around her legs. It would've just dragged her down to it's 'body', but it remembered the laser pointer. It remembered the pain, it remembered her. Blinding pain arced through her back to reach the bottom of her skull as she slid down the far wall. She opened her eyes to Spike, nearly covered in the black form, only his head and hands currently free from it's hold, still rifling through her bags, the look on his face detailing his desperation and terror in horrible detail. She had seen that expression before. She turned away, she couldn't watch his final moments. She knew it was done, no glory, no apology, just an unlucky slip at the wrong time.

Green light flooded the basement. It penetrated physical objects, filling the entire area. Derpy closed her eyes, she wasn't sure how, but it somehow made it worse. It didn't dull the brightness, but it was _supposed_ to, and the light seemed even more agonizingly bright. There was a slight pause, a shudder ran through the Effect, followed by an alien scream. It didn't carry far, nopony else in Ponyville could hear it, but that thought didn't comfort Derpy as she crushed her ears into the sides of her head, the sound abused her for a moment, and then was gone. A small burp came from Spike's direction.

She rolled onto her belly, blanching as she lifted herself off the ground. Everything was painful, everything ached and stabbed at the same time.

'Why didn't you tell me you had liquid light?' Spike waved the small glass in front of her, his voice painfully loud. So that's what the thing was, maybe she should read more books. She gave a semi-congratulatory pat on the back. Spike arched and hissed at her touch. She looked at his scales, where the Effect had touched, the purple had become an angry pink. Spike still smiled, a wobbling, flimsy thing, created to prevent her from feeling bad. It didn't work. She pulled her hoof away, suddenly guilty. She had come out relatively unscathed, although she didn't feel that way, but at least she still had all her hair, which was a better result than last time.

Derpy offered to buy Spike lunch, but he declined. Derpy was secretly happy at this, all she wanted to do was go to bed, and she only really offered to be polite. He had saved both their lives, she thought that was worth the twelve bits of gems he might have eaten.

She dragged the sheet laboriously over her, admonishing herself for leaving her saddlebags at Twilight's, but she could get them tomorrow. Her generous allotted payment materialized on the table. Celestia's gratitude was one of the few that could be directly banked.


End file.
